1.9.10: XnView.db overwrite while busy when opening a second instance of XnViewMP

[Rhodenspire]

XnView: MP 1.9.10 - Flatpak & Appimage 64 bit
OS: Linux, Endeavour OS 64-bit, xfs file system

When opening a second instance of XnViewMP while the first instance is busy accessing the database (generating thumbnails or just accessing it in general), the second instance overwrites XnView.db with a new one.

Effect: You lose all tags, color labels, etc. new thumbnails have to be generated as well.

To reproduce:
1. Open XnViewMP and navigate to a folder with a lot of images
2. While that instance is busy generating thumbnail or loading thumbnails from the Thumb.db file open a new instance of XnViewMP

Actual behaviour (bug): When a second instance of XnViewMP tries to access XnView.db while the first instance is busy using it, it overwrites XnView.db with a new empty one

Expected behaviour: For the database to not be overwritten while it's busy

I've noticed this happening since 1.9.6, I tried to make it happen in 1.9.5, but it's strange. In 1.9.5 if you open a second instance while the database is busy it starts blank like 1.9.6+, but it doesn't overwrite XnView.db; if the database is not busy, it opens just fine. I've tried to reproduce this in Windows 11, but it seems to be unaffected.

[alee001]

Just passing by…

I often use two MP windows simultaneously. MP updates the data based on the currently used window, even when switching windows, until the last window closes and updates the database and location—this is normal.

I think the problem is that MP shouldn't be loading thumbnails from two windows simultaneously. If loading is slow, taking tens of seconds or more for over a thousand folders, then that's a bug. (This happened in previous versions.)